1. Field of the Invention
The present invention pertains to a nasal mask and to a pressure support system using such a mask to interface with the airway of a patient, and, in particular, to a nasal mask that includes a seal member having a nose receiving cavity defining a contoured reinforcement area, a collar coupled to the seal member, and a conduit coupling member, and to a system to supply a flow of gas to a patient that incorporates such a nasal mask.
2. Description of the Related Art
A variety of respiratory masks are known that have flexible seals and cover the nose, mouth, or both of a human user and are designed to create a seal against the user""s face. Because of the sealing effect that is created, gases can be provided at a positive pressure within the mask for consumption by the user. The uses for such masks range from high altitude breathing (i.e., aviation applications) to mining and fire fighting applications, to various medical diagnostic and therapeutic applications. For example, such masks are used in the delivery of continuous positive airway pressure (CPAP) or variable airway pressure, which varies with the patient""s respiratory cycle or which varies with the condition of the patient, to treat a medical disorder, such as sleep apnea syndrome, obstructive sleep apnea (OSA), congestive heart failure, and cheynes-stokes respiration.
A requisite of such respiratory masks is that they provide an effective seal against the user""s face to prevent leakage of the gas being supplied. Commonly, in prior mask configurations, a good mask-to-face seal has been attained in many instances only with considerable discomfort to the user. This problem is most crucial because such masks are typically worn for an extended period of time. One concern in such a situation is that a user may avoid wearing an uncomfortable mask, defeating the purpose of the prescribed pressure support therapy.
A low contact nasal mask, referred to as the Simplicity Nasal Mask, which is manufactured and sold by Respironics, Inc. of Pittsburgh, Pa., includes a seal member defined from a unitary piece of elastomeric material having side walls including three ribs on each side of the seal member to provide structural support for the seal member. However, this configuration may no optimize patient comfort while providing good structural support for the seal, as least for some patients.
An advantage exists, therefore, for a respiratory mask that affords an effective yet comfortable seal and overcomes the shortcomings of conventional respiratory masks.
The present invention provides an improved respiratory mask that reliably and comfortably seals a user""s face by providing a nasal mask assembly that includes a seal member defined from a unitary piece of elastomeric material. The seal member includes a nose receiving cavity, a first end portion, and a second end portion opposite the first end portion. A first opening is defined in the first end portion to receive at least a portion of a nose of a patient such that nares of the patient communicate with the receiving cavity.
The seal member also includes a neck portion defined in the second end portion and a second opening defined in the neck portion to provide an inlet for breathing gas from an external source and an outlet for the patient""s expelled gases. Because the seal member is formed from a relatively flexible material, the seal member of the present invention includes a structural reinforcement area on the side walls of the seal member contoured to the shape of a patient""s face. The reinforcement area comprises a saddle shaped contoured area on each side of the seal member. Each saddle shaped area has an upper and a lower protrusion portion for providing supporting contact with the face. The nasal mask assembly also includes a collar coupled to the neck portion. The collar includes a plurality of headgear attachment points spaced apart from the seal member. In addition, the nasal mask assembly includes a conduit coupling member coupled to either the neck portion of the seal member and the collar for use in attaching the nasal mask assembly to a ventilator or pressure support device.
Additionally, a system for delivering a flow of gas to a patient is provided that includes a gas flow generating device capable of producing a flow of gas and a conduit having a first end portion operatively coupled to the gas flow generating device and a second end portion. The conduit carries the flow of gas from the gas flow generating device. The system includes a nasal mask assembly as described above operatively coupled to the second end portion of the conduit.
These and other features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.